*2.2. XRD Analysis of CS/PVOH/HNT and CS/PVOH/TO@HNT Films*

XRD patterns of all obtained CS/PVOH/HNT and CS/PVOH/TO@HNT films as well as of films from pure CS/PVOH gels are shown in Figure 2. The pattern of films from pure CS/PVOH gels exhibits three broad peaks at 8.5◦ , 11.5◦ , 18.5◦ , and 23◦ are observed. The peaks at 8.5◦ and 11.4◦ indicate the CS's hydrated crystallite structure due to the insertion of water molecules in the CS's crystal lattice [50,51] while the third peak at 18.5◦ is assigned to the CS's regular crystal lattice [51,52]. The later broaden peak around 23◦ assigned to the amorphous structure of CS [51,52]. *Gels* **2022**, *8*, x FOR PEER REVIEW 5 of 25

**Figure 2.** XRD plots of (1) CS/PVOH film, (2) CS/PVOH/5HNT, (3) CS/PVOH/10HNT, (4) CS/PVOH/15HNT, (5) CS/PVOH/5TO@HNT, (6) CS/PVOH/10TO@HNT, and (7) CS/PVOH/15TO@HNT nanocomposite films. **Figure 2.** XRD plots of (1) CS/PVOH film, (2) CS/PVOH/5HNT, (3) CS/PVOH/10HNT, (4) CS/PVOH/15HNT, (5) CS/PVOH/5TO@HNT, (6) CS/PVOH/10TO@HNT, and (7) CS/PVOH/15TO@HNT nanocomposite films.

In the case of CS/PVOH/xTO@HNT film patterns, the diffraction peaks of HNT at 2θ = 11.7° do not observe for x = 5% wt. and 10% wt., i.e.*,* line (5) and (6), and observed slightly for x = 15%wt., i.e.*,* line (7). In the cases of CS/PVOH/xHNT, the HNT peak does not observe for x = 5%wt., i.e.*,* line (2), and is observed slightly for x = 10%wt. and 15%wt. i.e.*,* In the case of CS/PVOH/xTO@HNT film patterns, the diffraction peaks of HNT at 2θ = 11.7◦ do not observe for x = 5% wt. and 10% wt., i.e., line (5) and (6), and observed slightly for x = 15%wt., i.e., line (7). In the cases of CS/PVOH/xHNT, the HNT peak does not observe for x = 5%wt., i.e., line (2), and is observed slightly for x = 10%wt. and

lines (3) and (4). These results indicate that in cases of TO@HNT the optimum dispersion of nanohybrid achieved for concentration x = 10%wt., while for concentration x = 15%wt. the aggregation started. In cases of HNT the optimum dispersion of nanohybrid achieved

started. The absence of shift of basal HNT's peak at 2θ = 11.7° indicates that CS/PVOH chains can not intercalate HNT's interlayer space [53]. The absence of HNT's peak in all CS/PVOH/TO@HNT films implied the higher dispersity of modified TO@HNT hybrid nanostructure than pure HNT in the CS matrix. The high dispersion of HNT and

In Figure 3 representative spectra of pure CS/PVOH, CS/PVOH/HNT, and

CS/PVOH/TO@HNT are observed.

TO@HNT in the CS matrix is beneficial for such nanocomposite films.

*2.3. FTIR Spectroscopy of CS/PVOH/HNT and CS/PVOH/TO@HNT Films*

15%wt. i.e., lines (3) and (4). These results indicate that in cases of TO@HNT the optimum dispersion of nanohybrid achieved for concentration x = 10%wt., while for concentration x = 15%wt. the aggregation started. In cases of HNT the optimum dispersion of nanohybrid achieved for concentration x = 5%wt. while for concentration x = 10%wt. or greater the aggregation started. The absence of shift of basal HNT's peak at 2θ = 11.7◦ indicates that CS/PVOH chains can not intercalate HNT's interlayer space [53]. The absence of HNT's peak in all CS/PVOH/TO@HNT films implied the higher dispersity of modified TO@HNT hybrid nanostructure than pure HNT in the CS matrix. The high dispersion of HNT and TO@HNT in the CS matrix is beneficial for such nanocomposite films.
